PCIe interlane length matching

Hello,

I’m designing a board and using UPHY RX/TX 12 ~ 19 as a x8 bus.

Similarly, I’m also using UPHY RX/TX 22,23,10,11 as a x4 bus.

Is there any requirement for length matching between the lanes in the same bus?

Usually we have requirements for length matching all TXs and all RXs in the same bus, but I can’t find them in the Design Guide.

Best regards.